Change TMemCheck::Action to return whether to break rather than calling
PPCDebugInterface::BreakNow, as this simplified the implementation; then
remove said method, as that was its only caller.  One "interface" method
down, many to go...

- Move JitState::memcheck to JitOptions because it's an option.
- Add JitOptions::fastmem; switch JIT code to checking that rather than
  bFastmem directly.
- Add JitBase::UpdateMemoryOptions(), which sets both two JIT options
  (replacing the duplicate lines in Jit64 and JitIL that set memcheck
  from bMMU).
  - (!) The ARM JITs both had some lines that checked js.memcheck
    despite it being uninitialized in their cases.  I've added
    UpdateMemoryOptions to both.  There is a chance this could make
    something slower compared to the old behavior if the uninitialized
    value happened to be nonzero... hdkr should check this.
- UpdateMemoryOptions forces jo.fastmem and jo.memcheck off and on,
  respectively, if there are any watchpoints set.
- Also call that function from ClearCache.
- Have MemChecks call ClearCache when the {first,last} watchpoint is
  {added,removed}.

Enabling jo.memcheck (bah, confusing names) is currently pointless
because hitting a watchpoint does not interrupt the basic block.  That
will change in the next commit.

Code style updates.

Fixed watch labels from being truncated at the first whitespace.

Made the floating windows toolbars dockable.
Scaled down the breakpoint toolbar icons to 16x16.